Boring bar pilot support



June 30, .1953 E. SPERISEN 2,543,554

BORING BAR PILOT SUPPORT Filed Jan. 14, 1948 2 Sheets-Sheet 1 ErnestSperz'sen ATTORNEY June 30, 1953 E. SPERISEN BORING BAR PILOT SUPPORTFiled Ja.n. 14, 1948 2 Sheets-Sheet 2 1' JIMW" mu INVENTOR. Ernesl'Sperz'sen ATTORNEY:

Patented June 30, 1953 UNITED STATES H PATENT OFFICE BORING-BAR PILOTsueroirr argest s p errsen, traaison, 'Wi'a, assign or to Qrish'oltMachine com any, -Mad'ison, 'Wfs a 'cor pbrauonor WishonsinApplication-January 14, i948, sentimental 2 "flotilla.

This invention relates to a boring bar snot support. 7

The principal object of theini entionisto more accurately support thepilot 'andthereb'yprovide I substantially greater accuracy in thesupport of v the pilot.

The invention is illustrated in the accompanying drawing in which:

Figure 1 is a side elevation of parts of a'turret lathe with partsbroken away "and sectioned to show the pilot bearing construction;

Fig. 2 is a similar view of a horizontal boring mill showing a modifiedpilot bearing construction; and

Fig. 3 is a front elevationof the bearing showing the pilot in semen andthe passages in dotted line.

The invention utilizesajournal bearing fo'r'the pilot 2.

In Fig. 1 the journal hearing I is secured within the central bore of awork chuck 3 mounted on the end of a rotary lathe spindle 4, and thepilot 2 is carried at the end of a longitudinally movable boring bar 5secured to a turret 6 or the like of a lathe I.

In Fig. 2 the journal bearing I is secured axially of the work support 8of a horizontal boring mill, and the pilot 2 is carried at the end of arotary longitudinally movable boring bar 9.

The bearing I and pilot 2, in each instance, are disposed in axialalignment with each other so that the pilot enters through the bearingas the cutters Iii of the boring bar advance through the work. The pilotserves tosteady the boring bar and keep the cutters in alignment withthe projected opening to be bored in the workpiece at all times.

Heretofore, ordinary journal bearings have not been practical assupports for boring bar pilots due to the fact that the pilot carriedinto the bearing chips "and foreign matter which injured the bearing andmade it necessary to provide such large bearing clearances that accuracyof support for the pilot was not obtainable. This was particularlyso inalathesin'ce the hearing or the boring bar and 'it'spilot was non rotar yand would readily "retain foreign matter on their upwardl facing bearingsurfaces.

The present invention provides "a siin'ple and efficient means forremoving all foreign matter f om the su face "of 'thepilot immediatelyahead 'of its point of progressive -entry into the bearing. The use ofthe invention makes it possible to employ sinaller bearing clearancesand thereby to 'pro-vid'e'more accuratesup ort forthepilot.

'In'c'arryin'g outthe inventiona circumferential nozzle I I isprovidedat'the-i'ront fen'd'of-thebearing I with the 'iiiou'thofthenozzle facin'g longitudinally outward in a direction opposite to thedirectionof movement of the pilot 2 in entering the bearing.

Thenozzle I'I may be constructedas an inwardly facing groove -extendin'gcontinuously around the inside of thebearing I near its 'forwardens,with'the 'mouth'of the nozzle provided by machining the iront'lip [2 toa'largefinteriial diameter than that-'of'the bearing.

In general, it is sufficient opening for the mouth of the nozzle if thelip I2 hasa'bout two jthousandthsof an inch clearance from 'the' pilot"2. The'bearin'g may have substantially less than a thousandth of aninch clearance from "the pilot.

The nozzle c'ohstruetion' of Fig. 2 differs-from that of Fig. 1 only inthe fact that the lip I2 is provided by a. plate member secured to thefront of the bearing and partially closing a recess in the bearing tocomplete the nozzle groove referred to and provide the mouth for thenozzle, while in Fig. 1 the lip I2 is an integral part of the bearing Iand the nozzle groove and mouth are formed wholly by machining. Thenozzle may also be constructed of parts separable from the bearing as toinclude a second member, not shown but similar to the plate memberproviding lip I2 of Fig. 2, and which closely fits pilot 2 to preventescape of fluid toward the end of pilot 2 as does bearing I shown afterthe pilot has entered the bearing.

Air is supplied to nozzle II by a plurality of feeder passage I3disposed radially and preferably diagonally in the bearing. A suiiicientnumber of passages I3 should be employed to distribute the air uniformlyaround the circumference and provide a uniform blast of air forward- 31y out of the mouth of the nozzle throughout the circumference.

A header chamber I4 is provided at the outer circumference of thebearing member I to supply air equally to the several passages 13. Thechamber I4 may constitute merely a recess in the outer circumference ofthe bearing member which is closed by the body of the work chuck 3 orwork support 8 in which the bearing is mounted.

If desired the header chamber l4 may constitute a recess in the body ofthe outer member surrounding the bearing member I instead of a recess inthe bearing member itself or in combination with such a bearing memberrecess, as shown in Fig. 2.

Air is supplied to header chamber 14 through a passage l5 in the bodymember surrounding the bearing 1 and which connects with a conduit 18leading from a tank 11- of compressed air or other suitable source ofair pressure.

A valve I8 is disposed in conduit line I6 for manually or automaticallycontrolling the supply of air to the nozzle. In practice, the air may besupplied either continuously during the boring operation at asubstantially constant rate or it may be supplied in rapidlyintermittent blasts to more effectively dislodge foreign matter from thepilot. If the air is supplied before the pilot reaches the nozzle, theend of the pilot in passing the nozzle will be cleaned of foreign matterand will cause a blast of air to be directed toward the bearing to cleanthe latter as Well.

Since in the lathe illustrated in Fig. 1 the Work chuck 3 and itspassage I5 rotate with the spindle 4 it is necessary to provide a secondsealed header 19 between some part of the rotating mechanism and astationary member.

The header !9 may be located conveniently between the chuck 3 and thewall of the headstock 20, and be constructed as a hollow ring member 2|secured to the headstock and encircling the end of spindle 4. Passage ISin this embodiment leads through the body of the chuck 3 into thespindle 4 and then radially into the header chamber IS in member 21.

A suitable seal 22 may be provided in chamber 19 to prevent leakage ofair between the relatively rotating surfaces.

The air pressure employed should be sufficient to clean the pilot offoreign matter as it enters the bearing.

The invention may have various embodiments within the scope of theaccompanying claims.

I claim:

1. In a machine tool of the class described including a boring bar and awork support having a central opening to receive said bar, said worksupport and boring bar being relatively rotatable and axially movable onthe longitudinal axis of the bar and the bore to be formed in the Work,said boring bar being supported at one end and adapted to carry a tooladjacent thereto and having a cylindrical pilot at the other end thereofdisposed to pass through a rough opening in the work as the toolapproaches the work, an annular nozzle supported and disposed to receivesaid pilot prior to the engagement of the tool with the work, saidnozzle having a circular chamber connected to a supply of fluid underpressure and defined by annular members dimensioned to fit said pilotand direct the discharge of fluid therebetween along the surface of thepilot to remove foreign matter therefrom, and a journal bearing carriedwithin the opening of said work support to receive and guide said pilotafter the end of the pilot has passed the chamber of said nozzle andforeign matter has been removed by the fluid from the end of the pilotbefore entering said bearing.

2. The invention as defined in claim 1 wherein a clearance is providedbetween the end of the pilot and the annular member which is firstentered by the end of the pilot, whereby the end of the pilot inapproaching the other annular member effects a construction between thepilot and said other member which at least momentarily causes a part ofthe fluid to be directed through said bearing to remove any foreignmatter therefrom before said pilot enters the same.

ERNEST SPERISEN.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 1,056,282 Koerting et al Mar. 18, 1913 1,099,500 Hesketh June9, 1914 1,846,986' Bogart Feb. 23, 1932 1,906,715 Penick May 2, 19332,295,856 I Mallory Sept. 15, 1942 2,383,094 Walder Aug. 21, 19452,429,516 Jergens Oct. 21, 1947 I FOREIGN PATENTS Number Country Date306,295 Germany June 27, 1918

